Miley Cyrus Calls Justin Gaston 'Really Cute'

As she approaches her 16th birthday, Miley Cyrus says she is learning to keep her guard up.

"I think you have to be really careful about the people you trust," the Hannah Montana star, who turns 16 on Nov. 23, tells Ellen DeGeneres in an interview set to air Nov. 20. "There [are] very few, two or three people that I would actually go to with anything and know that it would never leave the room," she says. "Two of those are my parents."

And the other person in Cyrus's inner circle? Boyfriend Justin Gaston, 20. Giggling in her Ellen interview, Cyrus says the two have been dating for "a couple months."

She adds: "He's a singer, he's really cute, and he's nice and he's a Christian and I really like that."

Cyrus also shares how hard it was to make new friends in Hollywood after leaving Nashville. While many of her pals are also in the business because it is "easier," even that can become a challenge.

"I think that's what's really great, because you can relate to each other that way," she says, "but it still makes it hard because you still never know when someone's career is up and down."